device: Add device support for the Broadcom Raspberry PI

device: Add device support for the Broadcom Raspberry PI

Add mkspec for the Raspberry PI platform to be used in conjunction with the
-device support in configure. This allows you to build Qt with the
application libraries provided by the Raspberry PI foundation.

The Raspberry PI is described here:

http://en.wikipedia.org/wiki/Raspberry_Pi

and its use with Qt is documented here:

http://wiki.qt-project.org/Devices/RaspberryPi

Change-Id: Ib8d11d0a469edaaf34ccc04cf33a42a725fc2bdb
Reviewed-by: Girish Ramakrishnan <girish.1.ramakrishnan@nokia.com>
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>